Effects of comparative claims in prescription drug direct-to-consumer advertising on consumer perceptions and recall.

Although pharmaceutical companies cannot make comparative claims in direct-to-consumer (DTC) ads for prescription drugs without substantial evidence, the U.S. Food and Drug Administration permits some comparisons based on labeled attributes of the drug, such as dosing. Researchers have examined comparative advertising for packaged goods; however, scant research has examined comparative DTC advertising. We conducted two studies to determine if comparative claims in DTC ads influence consumers' perceptions and recall of drug information. In Experiment 1, participants with osteoarthritis (n=1934) viewed a fictitious print or video DTC ad that had no comparative claim or made an efficacy comparison to a named or unnamed competitor. Participants who viewed print (but not video) ads with named competitors had greater efficacy and lower risk perceptions than participants who viewed unnamed competitor and noncomparative ads. In Experiment 2, participants with high cholesterol or high body mass index (n=5317) viewed a fictitious print or video DTC ad that had no comparative claim or made a comparison to a named or unnamed competitor. We varied the type of comparison (of indication, dosing, or mechanism of action) and whether the comparison was accompanied by a visual depiction. Participants who viewed print and video ads with named competitors had greater efficacy perceptions than participants who viewed unnamed competitor and noncomparative ads. Unlike Experiment 1, named competitors in print ads resulted in higher risk perceptions than unnamed competitors. In video ads, participants who saw an indication comparison had greater benefit recall than participants who saw dosing or mechanism of action comparisons. In addition, visual depictions of the comparison decreased risk recall for video ads. Overall, the results suggest that comparative claims in DTC ads could mislead consumers about a drug's efficacy and risk; therefore, caution should be used when presenting comparative claims in DTC ads.